"That is how it will probably pan out and South Coast Arden will be hard to beat if it does," admits Purdon.
"He was very good after having no luck last week and he loves being in front.
"Our horse is really well too but if we are sitting parked outside Mango's horse it is going to be close."
Self Assured is the best pacer in the country and has looked in the zone this campaign but if that scenario unfolds then South Coast Arden becomes very backable if he touches $3.
Mangos could also be the thorn in the side of the Purdon/Cullen four reps in the $50,000 Alabar Classic in which they have favourites Akuta and Franco Indie.
Both had their cloaks of invincibility torn in the mega upset Harness Millions three weeks ago and the three-year-old division looks far more open than it did.
Purdon says the Millions, won at 100-1 by another in tonight's field in Magic Four, still mystifies him.
"I am not sure if our big two only went okay that night because they were flattened by the week before or because of how hard they went early.
"I worked them on Wednesday morning and they are both really well, all four of ours in that race are, so we will see how they bounce back."
Purdon rates Akuta the stable's best chance from barrier two but warns it may not be a simple lead and win job in his redemption race.
"We know ours are still very good horses but I'd be lying if I didn't say that last race changed our confidence levels a bit," says Purdon.
"But I think both of them will be better with a trail this week." Enter Mangos again, this time driving massive improver Beach Ball who while drawn wide but could press forward and lead.
He did just that at Alexandra Park last week and after over-racing because he was touching the sulky wheels with his back hooves, he cleared out to win by 13 and a half lengths in 2:37 for 2200m, which would severely test those against him tonight.
Suggesting Beach Ball was as good as Akuta or Franco Indie a month ago would have sounded like lunacy but a lot has changed with this crop in that time and tonight's race could cement further change or reinstate order.
The other highlight tonight should see Purdon's filly True Fantasy win the Peter Breckon Memorial as he says she is training well and spot on, while Tony Herlihy is the trainer-driver to follow in the juvenile races with The Notorious R B G (race 5) and Seve (race 7) very hard to beat.